textproduct: Quad Cities

KEY MESSAGES

- Seasonable temperatures, dry conditions, and some hazy skies Thursday.

- Widespread showers and thunderstorms likely Friday. There is a 70-80% chance of rainfall amounts over 1". No severe weather is expected.

SHORT TERM /THROUGH THURSDAY/

Issued at 205 PM CDT Wed Jul 29 2026

Seasonable temperatures and dry conditions were seen today, as high pressure dropped south over southeast WI and the Great Lakes. Dewpoints are also 4 to 10 degrees lower compared to 24hrs ago, making it feel more tolerable outside. Visible satellite shows a Cu field across central and northeast IA, with recent trends showing smoke aloft beginning to thin over the CWA.

Quiet conditions will continue through the evening/overnight hours, as surface high pushes south over northern IL. As winds go calm, some shallow fog is possible in the Rock river valley tonight. Overnight lows to drop into the lower 60s.

Thursday...a rinse and repeat forecast is expected with mostly sunny skies, some haze from upstream wildfires, and similar afternoon highs to today reaching the mid to upper 80s. Despite deep mixing, forecast soundings show a dry column and very weak winds through 500mb leading to a persistence forecast.

LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/

Issued at 205 PM CDT Wed Jul 29 2026

Thursday Night through Friday...a shortwave currently over southwest UT, will round the edge of the upper ridge and move over the northern Plains/Midwest as a positively tilted shortwave bringing rain chances to the region. A strong LLJ coupled with increasing low level moisture will allow scattered showers and thunderstorms to develop across western and central IA nearing our CWA border by 12z Friday. Forecast soundings and moisture transport vectors keep the deeper moisture over central IA prior to 12z Friday and thus the onset of rain may be delayed slightly. Large scale forcing will increase through the day Friday and with deep warm cloud depths (4500m) and PWs rising over 2", efficient rain processes to allow for widespread showers. With MUCAPE values between 600-1000 J/Kg and marginal mid level lapse rates across the southern half of the CWA, can't rule out some embedded thunderstorms but overall coverage should be quite limited leading to lower but steady rainfall rates. Available instability will be the limiting factor to organized convection Friday. New model guidance continues to show different surface low tracks as noted in last night's forecast discussion. A northerly track still shown by the ECMWF, would favor highest QPF totals over the northern third whereas the NAM/GFS/RRFS solutions show a southerly track over southern IA into eastern MO favoring 2+" totals over the Hwy 30 to I-80 corridor. The WPC/NBM forecast currently favors the northerly track, but further refinements in the heaviest axis is likely in the next 24-36 hours. Regardless, 24-hr rainfall totals over 1" is becoming more likely for much of the CWA with NBM probabilities now over 70% area-wide! A good soaking rain will be very welcome and will also keep us cooler Friday, with highs only in the 70s.

Saturday...any lingering showers to move and exit to the southeast by mid-day. A tight pressure gradient behind the departing system to bring a period of gusty northerly winds up to 30 mph and combined with wrap around clouds will make it feel more like late August. Afternoon highs to top out in the 70s, coolest east of the MS RVR.

Sunday through Wednesday...dry conditions and seasonable temperatures are forecast to start the new week, as an upper ridge moves into the upper Midwest behind our departing system tracking over the Ohio river valley. Active storm track to remain over the northern Plains and southern Canada. Model ensembles show a transition to a zonal flow aloft mid to late week, leading to warmer temperatures and additional rain chances.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 619 PM CDT Wed Jul 29 2026

High pressure is forecast to very slowly move from eastern Illinois into northwest Indiana over the TAF period. This will keep light south to southeasterly flow across the area through the period. Winds will be light through mid morning before gradually increase to 5 to 8 knots through the remainder of the area. High clouds will slowly increase from west to east after 21 UTC Thursday. VFR conditions are expected through the period.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.